Make Board a type synonym isntead of a newtype

app/Main.hs

@@ -3,8 +3,10 @@ module Main where
 import           Lib
 
 main :: IO ()
-main = putStrLn $ printBoard (Board
+main =
+  putStrLn $
+  printBoard
     [ [Bomb Revealed, Value 1 Revealed, Value 0 Revealed]
     , [Value 1 Revealed, Value 1 Revealed, Value 0 Revealed]
     , [Value 0 Revealed, Value 0 Revealed, Value 0 Revealed]
-                      ])
+    ]

src/Lib.hs

@@ -3,16 +3,12 @@ module Lib
   , flagTile
   , revealTile
   , printBoard
-  , Board(..)
+  , Board
   , Tile(..)
   , TileState(..)
   ) where
 
-newtype Board =
+type Board = [[Tile]]
-  Board
-    { unBoard :: [[Tile]]
-    }
-  deriving (Eq, Show)
 
 data Tile
   = Value Int TileState
@@ -28,41 +24,39 @@ data TileState
 type Coordinates = (Int, Int)
 
 createBoard :: Int -> Int -> [Coordinates] -> Board
-createBoard boardWidth boardLength bombs = Board $ foldr placeBomb createClearBoard bombs
+createBoard boardWidth boardLength = foldr placeBomb createClearBoard
   where
     createClearBoard = replicate boardLength createClearLine
     createClearLine = replicate boardWidth (Value 0 Hidden)
-    placeBomb (x, y) board =
+    placeBomb (x, y) board = mapAroundTile incrementValueTile (x, y) $ replaceTile board (x, y) (Bomb Hidden)
-      unBoard $ mapAroundTile incrementValueTile (x, y) $ replaceTile (Board board) (x, y) (Bomb Hidden)
+    incrementValueTile (x, y) board =
-    incrementValueTile (x, y) (Board board) =
+      case findTile board (x, y) of
-      case findTile (Board board) (x, y) of
+        (Just (Value value Hidden)) -> replaceTile board (x, y) (Value (value + 1) Hidden)
-        (Just (Value value Hidden)) -> replaceTile (Board board) (x, y) (Value (value + 1) Hidden)
+        _ -> board
-        _ -> Board board
 
 flagTile :: Coordinates -> Board -> Board
-flagTile (x, y) (Board board) =
+flagTile (x, y) board =
-  case findTile (Board board) (x, y) of
+  case findTile board (x, y) of
     (Just tile) -> flagHiddenTile tile
-    Nothing     -> Board board
+    Nothing     -> board
   where
-    flagHiddenTile (Value value Hidden) = replaceTile (Board board) (x, y) (Value value Flagged)
+    flagHiddenTile (Value value Hidden) = replaceTile board (x, y) (Value value Flagged)
-    flagHiddenTile (Bomb Hidden) = replaceTile (Board board) (x, y) (Bomb Flagged)
+    flagHiddenTile (Bomb Hidden) = replaceTile board (x, y) (Bomb Flagged)
-    flagHiddenTile _ = Board board
+    flagHiddenTile _ = board
 
 revealTile :: Coordinates -> Board -> Board
-revealTile (x, y) (Board board) =
+revealTile (x, y) board =
-  case findTile (Board board) (x, y) of
+  case findTile board (x, y) of
     (Just tile) -> revealHiddenTile tile
-    Nothing     -> Board board
+    Nothing     -> board
   where
-    revealHiddenTile (Value 0 Hidden) =
+    revealHiddenTile (Value 0 Hidden) = mapAroundTile revealTile (x, y) $ replaceTile board (x, y) (Value 0 Revealed)
-      mapAroundTile revealTile (x, y) $ replaceTile (Board board) (x, y) (Value 0 Revealed)
+    revealHiddenTile (Value value Hidden) = replaceTile board (x, y) (Value value Revealed)
-    revealHiddenTile (Value value Hidden) = replaceTile (Board board) (x, y) (Value value Revealed)
+    revealHiddenTile (Bomb Hidden) = revealAll board
-    revealHiddenTile (Bomb Hidden) = revealAll (Board board)
+    revealHiddenTile _ = board
-    revealHiddenTile _ = Board board
 
 revealAll :: Board -> Board
-revealAll (Board board) = Board $ map revealLine board
+revealAll = map revealLine
   where
     revealLine = map revealSingleTile
     revealSingleTile (Value value Hidden) = Value value Revealed
@@ -70,26 +64,26 @@ revealAll (Board board) = Board $ map revealLine board
     revealSingleTile tile                 = tile
 
 replaceTile :: Board -> Coordinates -> Tile -> Board
-replaceTile (Board board) (x, y) tile =
+replaceTile board (x, y) tile =
   let (firstRows, line:lastRows) = splitAt y board
       (firstTiles, _:lastTiles) = splitAt x line
-   in Board $ firstRows ++ (firstTiles ++ tile : lastTiles) : lastRows
+   in firstRows ++ (firstTiles ++ tile : lastTiles) : lastRows
 
 findTile :: Board -> Coordinates -> Maybe Tile
-findTile (Board board) (x, y) =
+findTile board (x, y) =
-  if not (coordinatesExists (Board board) (x, y))
+  if not (coordinatesExists board (x, y))
     then Nothing
     else Just $ board !! y !! x
 
 coordinatesExists :: Board -> Coordinates -> Bool
-coordinatesExists (Board board) (x, y) = isPositive && isYWithinTheBoard board && isXWithinTheBoard board
+coordinatesExists board (x, y) = isPositive && isYWithinTheBoard board && isXWithinTheBoard board
   where
     isPositive = x >= 0 && y >= 0
     isYWithinTheBoard = (> y) . length
     isXWithinTheBoard = any ((> x) . length)
 
 printBoard :: Board -> String
-printBoard (Board board) = concatMap printLine board
+printBoard = concatMap printLine
   where
     printLine line = concatMap printTile line ++ "\n"
     printTile (Bomb Hidden)      = "#"

test/Spec.hs

@@ -5,12 +5,8 @@ import           Test.Tasty.HUnit
 main :: IO ()
 main = defaultMain $ testGroup "Minesweeper tests" [flagTileTest, revealTileTest, createBoardTest]
 
-emptyBoard :: Board
-emptyBoard = Board []
-
 hiddenBoard :: Board
 hiddenBoard =
-  Board
   [ [Bomb Hidden, Value 1 Hidden, Value 0 Hidden]
   , [Value 1 Hidden, Value 1 Hidden, Value 0 Hidden]
   , [Value 0 Hidden, Value 0 Hidden, Value 0 Hidden]
@@ -18,7 +14,6 @@ hiddenBoard =
 
 revealedBoard :: Board
 revealedBoard =
-  Board
   [ [Bomb Revealed, Value 1 Revealed, Value 0 Revealed]
   , [Value 1 Revealed, Value 1 Revealed, Value 0 Revealed]
   , [Value 0 Revealed, Value 0 Revealed, Value 0 Revealed]
@@ -28,17 +23,15 @@ flagTileTest :: TestTree
 flagTileTest =
   testGroup
     "Flag tile"
-    [ testCase "Empty board" $ flagTile (1, 1) emptyBoard @?= emptyBoard
+    [ testCase "Empty board" $ flagTile (1, 1) [] @?= []
     , testCase "Flag bomb tile" $
       flagTile (0, 0) hiddenBoard @?=
-      Board
       [ [Bomb Flagged, Value 1 Hidden, Value 0 Hidden]
       , [Value 1 Hidden, Value 1 Hidden, Value 0 Hidden]
       , [Value 0 Hidden, Value 0 Hidden, Value 0 Hidden]
       ]
     , testCase "Flag value tile" $
       flagTile (2, 0) hiddenBoard @?=
-      Board
       [ [Bomb Hidden, Value 1 Hidden, Value 0 Flagged]
       , [Value 1 Hidden, Value 1 Hidden, Value 0 Hidden]
       , [Value 0 Hidden, Value 0 Hidden, Value 0 Hidden]
@@ -51,18 +44,16 @@ revealTileTest :: TestTree
 revealTileTest =
   testGroup
     "Reveal tile"
-    [ testCase "Empty board" $ revealTile (1, 1) emptyBoard @?= emptyBoard
+    [ testCase "Empty board" $ revealTile (1, 1) [] @?= []
     , testCase "Reveal bomb tile" $ revealTile (0, 0) hiddenBoard @?= revealedBoard
     , testCase "Flag 0 value tile" $
       revealTile (2, 0) hiddenBoard @?=
-      Board
       [ [Bomb Hidden, Value 1 Revealed, Value 0 Revealed]
       , [Value 1 Revealed, Value 1 Revealed, Value 0 Revealed]
       , [Value 0 Revealed, Value 0 Revealed, Value 0 Revealed]
       ]
     , testCase "Flag non 0 value tile" $
       revealTile (1, 0) hiddenBoard @?=
-      Board
       [ [Bomb Hidden, Value 1 Revealed, Value 0 Hidden]
       , [Value 1 Hidden, Value 1 Hidden, Value 0 Hidden]
       , [Value 0 Hidden, Value 0 Hidden, Value 0 Hidden]
@@ -75,18 +66,16 @@ createBoardTest :: TestTree
 createBoardTest =
   testGroup
     "Create board"
-    [ testCase "Empty board" $ createBoard 0 0 [] @?= emptyBoard
+    [ testCase "Empty board" $ createBoard 0 0 [] @?= []
     , testCase "3x3 single bomb" $ createBoard 3 3 [(0, 0)] @?= hiddenBoard
     , testCase "3x3 three bombs" $
       createBoard 3 3 [(0, 0), (1, 1), (2, 2)] @?=
-      Board
       [ [Bomb Hidden, Value 2 Hidden, Value 1 Hidden]
       , [Value 2 Hidden, Bomb Hidden, Value 2 Hidden]
       , [Value 1 Hidden, Value 2 Hidden, Bomb Hidden]
       ]
     , testCase "3x3 four bombs" $
       createBoard 3 3 [(0, 1), (1, 1), (2, 1), (1, 0)] @?=
-      Board
       [ [Value 3 Hidden, Bomb Hidden, Value 3 Hidden]
       , [Bomb Hidden, Bomb Hidden, Bomb Hidden]
       , [Value 2 Hidden, Value 3 Hidden, Value 2 Hidden]